Strange Problem with old Northern 1160 (20ton) splitter

quid_non · Mar 9, 2015

Split a lot of wood with this beast for over 20 years.
Last year started to have intermittent problems with splitting and return speed - I replaced the 11GPM 2 stage Haldex pump with original from Northern - - seem to have fixed the problem until now.

Now, I get significant amount of "air" in oil and by eye the flow rate from the filter to the return reservoir just seems a bit slower and milky looking. This is accompanied by significantly increased time to split hardwood and an "explosive" pop when it does. Often, it spews oil (clearly mixed with air - foamy looking) from the axle reservoir.

Here what I have done so far:
- changed the oil and filter (25micron filter, Northern AW32 oil)
- replaced the inlet hose (from reservoir to pump with a sturdy non-collapse hose)
-cleaned the in-axle reservoir filter (filter that is immediately before and feeds the pump)
-checked and double check for any air leaks from the inlet side
- made sure I had plenty of oil and not overfilled
-checked to make sure the oil fill / breather valve on axle was not clogged
-put a pressure gauge in line (T fitting) from pump to inlet valve

Engine runs fine - checked the lovejoy connector - all is fine.

With the system running and no log in the splitter - when I put detent valve (Prince series ls 3000-1) in the position to move the ram - no pressure on gauge is registered but the ram moves fine at a slow and steady pace. When it reaches the end of travel, still no pressure developed UNTIL I continue to hold the lever then it reaches up to ~2700psi. When I reverse the valve direction, the pressure drops to zero immediately and stays there, the ram retracts fine at a good speed and no jerking motion. When it reaches the end of travel, still no pressure developed unless I keep the valve in the reversed position, then it develops ~2700psi for a moment. If I put the valve in the neutral position, pressure goes to zero and it will likely spew oil for the breather.

I'm thinking the pump is doing it's job - it develops pressure (not a two stages, but at max pressure). Could the problem be with detent valve or pump?

Any help appreciated!
Thanks

triptester · Mar 9, 2015

Your pressure readings seem normal. You will only see readings when there is resistance. Foaming of the fluid is normally caused by air being sucked into the system between the reservoir and pump.

Leejohn · Mar 9, 2015

Sound like you have oil going to and from the valve the wrong way. Detent should be on return,

oldtimer 66 · Mar 11, 2015

This is only a guess but could it be that the cylinder piston seal and or seals, not the rod seal and or rod seals that would be external leakage, are starting to leak AKA by pass after 20 years of service and when you dead head the cylinder, max pressure 2700 PSI, on the return you get pressure on both sides of the cylinder due to the leakage and the return to tank is under some elevated pressure versus just being displaced and it foams the oil because of that. That's a pretty good run on sentence wouldn't you think? Could this also contribute to the pop you say you are getting when you split some hard woods. I have no idea but there is probably some body that can identify your problem. Later.

quid_non · Mar 12, 2015

Thanks for all the comments and suggestions - - agree with triptester that I'm getting air form somewhere. Took the cylinder to a hydraulic repair shop and had it tested on their machine - all was fine, held pressure and no indication of oil bypass when one of the lines was removed and pressure applied. Now that still leaves the pump (new, replaced last year), hose connecting the oil reservoir tot he pump and the detent valve?

J_J · Mar 12, 2015

Several things don't seem right.

You say you have no pressure when splitting. If you spit anything with resistance, you are going to have pressure. The pressure should vary based on the resistance.

Is your detent return working?

Have you messed with the main relief or the detent relief.

What kind of gage are you using. Pressure limits.

If you have bubbles in the fluid, then you are sucking air or generating air by high pressure fluid over the relief valve.

You should really clean the input filter or remove it as the return filter should be good enough. About 10 to 25 microns.

You can't see an air leak, just the results of it.

You might try some thick grease around the fittings and hose.

quid_non · Mar 13, 2015

Thanks for the suggestions JJ - -please see comments below, I'm still trying to make this thing work again - - appreciate your (and every ones help)

J_J said:
Several things don't seem right.

You say you have no pressure when splitting. If you spit anything with resistance, you are going to have pressure. The pressure should vary based on the resistance.

No pressure when a log is absent and the ram is moving forward/backward. It does develop ~2700PSI when the ram reaches then end of travel

Is your detent return working?
Think so - the ram will return

Have you messed with the main relief or the detent relief.
No - - have not messed with any factory settings

What kind of gage are you using. Pressure limits.
oil filled, 5000PSI, plumbed in with a "T" connector between high pressure outlet from pumpand detent inlet

If you have bubbles in the fluid, then you are sucking air or generating air by high pressure fluid over the relief valve.
- agree with that for sure! How can I check this?

You should really clean the input filter or remove it as the return filter should be good enough. About 10 to 25 microns.
- good suggestion. The input filter (suction strainer mesh filter - was cleaned before I changed oil, but I will change again. The return filer is ~25 micron and not that old, perhaps change that again??)

You can't see an air leak, just the results of it.

You might try some thick grease around the fittings and hose.

- good suggestion, I'll try that this weekend and report back. Any possibility the pump (albeit only 1 yr old) is sucking air through shaft bearing? Can I check this?

Thanks again to all

J_J · Mar 13, 2015

If you know you have a good tight input hose and fittings, and the output hose is in a bucket ,then any bubbles generated would have to come from the pump.

However, relief valve over flow and cavitation will generate bubbles, and any high pressure leak might generate bubbles.

You might use a clear tube on the OUT hose before the tank and you can see bubbles. Not a good idea with hot fluid.

Try some grease on the shaft seal.

quid_non · Mar 13, 2015

yep=that solved the problem. Looks like the leak arose from the reservoir outlet to the pump inlet. Cleaned all connections and placed two clamps on the hoses. Splittin' like new now!
Was wrong on the date of this - this splitter been serving us well for over 28 years w/o any significant problems.

Thanks for your help and others!